HISTOGRAM /FILL

        [GREG1\]HISTOGRAM [Array_X Array_Y] [/BASE Ybase] /FILL [pen_num]

    The /FILL option indicates to fill the histogram with the colour of  the
    current  pen. Blanking is handled as for other histograms. Usually needs
    to be done in conjunction with the BASE  option  to  properly  fill  the
    histogram.  Pen_num  is  the  number (0-23) of the pen used to fill. The
    colors of the last 16 pens (8-23) can be changed by the user  (See  HELP
    LUT/PEN).